C4 gear ratios

[blubuckaroo]

Are all low and 2nd gear ratios the same for all factory C4 transmissions? I'd like to put in a wide ratio planetary set and wondered if those came equiped in any products. The ones in Broncos are 2.46 Lo - 1.46 2nd. Available aftermarket ratios are 2.75-1.57 & 2.92-1.68.

 

[Broncobowsher]

All factory C4s have the same ratios. No other ratios ever rolled out of Ford.
The aftermarket ratios are 100% aftermarket.

Beware that I have heard issues with some of the aftermarket gearsets not doing very well. Gears binding up and excessive wear. Many times these gearsets are designed for the drag race crowd with little for long term durability.

 

[blubuckaroo]

Thanks! good support here.

 

[JoseyWales]

I am running a C4 that I had built with the TCI 2.75:1 planetary. I love it for the gear reduction, but I can't testify for its longevity yet. It has 6 planet gears, so first gear whines loudly. Otherwise, so far so good.

 

[mr.n]

Do a Google search, you'll find plenty of these lower gears for the C4 that have broken apart.

On Ford Muscle a few guys who build C4's for resale bought some. They returned them without even installing them.
Can't find the link, but I've seen the pieces. When it breaks, hope you catch it in time so it doesn't trash the entire tranny.

Go with T-case gears, they are proven.

 

[blubuckaroo]

Do a Google search, you'll find plenty of these lower gears for the C4 that have broken apart.

On Ford Muscle a few guys who build C4's for resale bought some. They returned them without even installing them.
Can't find the link, but I've seen the pieces. When it breaks, hope you catch it in time so it doesn't trash the entire tranny.

Go with T-case gears, they are proven.

What are "T-case gears"?

 

[Broncobowsher]

T-case = Transfer case
Typically a set of these http://www.teraflex.biz/products/low20-bronco.html
But you can get much better pricing through other sources. I don't know who has the best deal today

 

[Z Bronco]

I have around 50K miles on a set of A1 transmission (purchased in 1996) lower C4 gear set (2.90 1st gear). I have not experienced anything negative so far. I also run a lower than stock stall speed converter. The trans guy who did the install was suspect on if the gear set would hold up, but so far so good. My combination of 351W, 4.10s, lower 1st and 2nd gear C4, and 35's has been a great street and trail combo.

 

[blubuckaroo]

T-case = Transfer case
Typically a set of these http://www.teraflex.biz/products/low20-bronco.html
But you can get much better pricing through other sources. I don't know who has the best deal today

The TC gear change isn't going to get me the change I need. I'm looking for more power only in the lower gears for pulling my trailer at high elevations with a lot of hairpin switchbacks. I already have 4.11 gears and don't want to go lower.

 

[JoseyWales]

The TC gear change isn't going to get me the change I need. I'm looking for more power only in the lower gears for pulling my trailer at high elevations with a lot of hairpin switchbacks. I already have 4.11 gears and don't want to go lower.

That's why I put the lower gears in the tranny instead of the TC... so the low first gear would come in handy pulling my boat. I hope the gears hold up better than the reports above though... makes me a little nervous.